Chronology of the adaptive response
The development of adaptive protection after pathogen entry or vaccination has a clear temporal dynamics:
- Inductive phase: lasts the first seven days.
- Effector phase: spans from week one to week three, when cytotoxic T-lymphocytes and delayed-type hypersensitivity effectors are maximally active.
- Antibody production: starts from the first week and persists for years.
- Protective immunity: begins to act from the first week.
- Immunological memory: originates by week 3–4 and persists for years.
Traditional and therapeutic vaccines
Classical vaccination aims to establish memory without disease. However, modern technologies apply vaccination principles for therapeutic purposes to reorient the immune response:
- In allergies: they induce a Th1-mediated response instead of the pathological Th2 pathway.
- In autoimmune processes: the goal is to induce anergy to self-antigens.
- In tumors: they enhance the Th1-pathway reaction against tumor antigens.
Role of adjuvants and antigen delivery
Adjuvants induce inflammation and stimulate innate immunity, helping to present the antigen to T cells:
- Mineral adjuvants (e.g., aluminum hydroxide) stimulate humoral response via Th2 cells.
- Pro-inflammatory stimuli (BCG) trigger a Th1 response.
- ISCOM complexes and liposomes deliver antigens into the cytosol or endosomal compartment to activate CD8+ lymphocytes.
Synthetic and antitumor agents
Synthetic vaccines are based on peptides conjugated to polymeric carriers, such as polyoxidonium. Prophylactic cancer vaccines, such as those against papillomavirus, aim to prevent cervical cancer and are administered to girls aged 12–13.
Memory chain: Induction (0-1 wk) -> Effectors and protection (1-3 wk) -> Memory (3-4 wk) -> Years of protection.
Class and exam questions
What is the main goal of traditional vaccination?
The main goal is to induce effective immunological memory without developing clinical manifestations of the disease.
What is the difference between complete and incomplete Freund's adjuvants?
Incomplete adjuvant forms an antigen depot to sustain the response upon repeated administrations. Complete adjuvant additionally contains BCG and is used to induce the primary immune response.
What role do aluminum hydroxide adjuvants play?
They act as a mineral adjuvant that stimulates T-cell-dependent humoral response mediated by Th2 cells.
What else to study on this topic
- Development of domestic HIV vaccines (CombiHIVvac, SAL-HIV)
- Mechanisms of granuloma formation in persistent infections
- Molecular pathways of macrophage activation via IFNγ and NO
- Comparison of pharmacotherapy and biotherapy
- Features of vector vaccines and plasmid constructs
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Other topics in the section "Immunity in defense and damage of the organism. Pathology of immunity"
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